High pressure guns are conventionally utilized at the discharge end of a high pressure water delivery line to selectively control the operative discharge of the high pressure water or other fluid to a nozzle portion of the gun via an internal valve mechanism disposed within the gun body and actuated by a trigger lever member pivotally secured to the gun body. The source of the high pressure fluid may produce the fluid at a particular flow rate such as, for example only, 11 gallons per minute. The high pressure gun may utilize a maximum of 10 gallons per minute. In such case, the fluid flow rate from the high pressure source must be adjusted to the flow rate that can be accepted by the gun.
Such flow control valves must be able to handle pressures of from 6,000 to 20,000 psi, be easy and economic to manufacture, simple to use in adjusting the flow rate and include safety features that prevent the valve from being accidentally disassembled while the high pressure fluid is present in the valve.
The present invention discloses a high pressure fluid flow control valve that is substantially cylindrical in shape, is less than 3 inches in diameter and is approximately 5 inches in height. It has a body portion with a fluid input port and a fluid output port. A valve seat is formed in the fluid output port for receiving a fluid seal. One end of a rotatable shaft or valve stem forms a seal with the valve seat in the fluid outlet port. The shaft is rotatably mounted in the body portion in threaded relationship such that rotation of the shaft moves it toward and away from the valve seat in the output orifice to control the degree of fluid flow between a fully closed and a fully opened valve position. The shaft has a first diameter with the threads on only a portion thereof and a smaller diameter above the threads such that the shaft can be rotated toward the output orifice to close the valve and to be threaded out of the body to disassemble the valve but can be moved toward the fully opened position only a limited distance to prevent disassembly of the valve accidentally with high pressure fluid applied thereto. The valve is rotatable to a plurality of fixed positions for controlling the degree of fluid flow between the input and output ports. Elongated spaced teeth surround at least a portion of the shaft and a spring-loaded ball, or elongated pin, is positioned on each side of the shaft for engaging the spaced teeth such that when one ball or pin is in the space between teeth, the other ball or pin is resting on a tooth thus allowing fixed positions of the shaft as the shaft is rotated. The number of fixed positions of the shaft is twice the number of spaced teeth on the shaft. Further, a radial groove extends partially into the body portion adjacent the input port. A pressure bleed port is formed on the interior of the input port and is coupled to the radial groove such that pressure in the valve chamber is prevented from exceeding a predetermined value. A fluid seal surrounds the rotatable valve stem or shaft above the input valve and below the shaft threads for forming a hollow chamber coupling the input port to the output port. A coupler, T-shaped in cross section, is attached to the valve stem such that rotation of the coupler rotates the threaded valve stem to control the degree of fluid flow through the valve between zero gallons per minute and a maximum number of gallons per minute. A substantially hollow U-shaped cap surrounds the body portion and is attached to the coupler such that rotation of the cap rotates the coupler and the threaded valve stem to control the degree of fluid flow through the valve. The U-shaped cap surrounds substantially the entire upper portion of the body thus protecting the upper body portion from shocks that might be generated external to the upper body portion. Thus, the upper body portion is less sensitive to damage from external forces. The U-shaped cap will only transmit rotation motion, or torque, to the valve stem.
Thus it is an object of the present invention to provide a high pressure control valve that can be placed between a high pressure fluid pump and a high pressure discharge source such as a fluid gun that can easily be adjusted to regulate the fluid flow to the gun in number of gallons per minute.
It is also an object of the present invention to provide a high pressure fluid flow control valve that has a ratchet device associated with a valve stem and a body portion for providing a plurality of fixed rotatable positions of the valve stem such that an adjustable fluid flow can be provided from a fluid inlet port to a fluid outlet port.
It is yet another object of the present invention to provide a high pressure fluid flow control valve that has an elongated shaft for providing an adjustable fluid flow and that can be rotated toward the output orifice to seal the output orifice or to dissemble the valve but can be moved toward the open position only a limited distance to prevent disassembly of the valve accidentally with high pressure applied thereto.